1. Technical Field
The present invention relates to an electronic weighing scale measuring mass of an object to be weighed, placed on the top surface of a top plate component, using load cell units.
2. Related Art
Many of general electronic weighing scales are configured as supporting a top plate component from the bottom side thereof, using four sets or around of load cell unit. Dead weight of an object to be weighed placed on the top plate component is loaded to these load cell units in a distributed manner. By summing up the measured values detected by the individual load cell units, mass of the object to be weighed may be measured.
The load cell unit is generally configured to have a plurality of strain gauges bonded to a sensing part of so-called strain generator. Known types of the strain generator include diaphragm type, shear beam type and so forth. These strain generators stand on a common ground in that the sensing part generates strain corresponding to load applied thereto. When dead weight of an object to be weighed is applied to the strain generator to thereby induce strain in the sensing part, amount of the strain is measured and converted into an electric signal by the strain gauge, thereby load of the object to be weighed applied to the individual load cell units may be determined.
In relation to this sort of invention, there has been known a measuring instrument typically described in Japanese Laid-Open Patent Publication No. 2001-228013. FIGS. 6A to 6C are drawings showing an appearance of this conventional measuring instrument. The conventional measuring instrument is configured by attaching weight sensor units (load cell units) to through-holes provided to an inner stage, and by supporting an outer stage (top plate component) allowing thereon placement of an object to be weighed by the load cell units from the bottom side.
There has been steadily growing demands for thinning of recent electronic weighing scales.
Thinning of the electronic weighing scales is advantageous in terms of improvement in space factor and transportability when they are placed upright or laid flat. Thinning of the electronic weighing scale further raises a large merit of allowing aged people, children and so forth to step on and step off more easily, when they are weighed.
In contrast to this, the conventional electronic weighing scale exemplified by the Japanese Laid-Open Patent Publication No. 2001-228013 could be thinned only to a limited degree, because the overall height of the electronic weighing scale was specified by a total thickness of at least height of the load cell units and thickness of the top plate component.
The present invention is conceived after considering the above-described problem, and is to provide an electronic weighing scale possibly be thinned.